iMPACT performs active readback for all FPGAs. As a result, for designs containing memory elements, the memory contents might be corrupted during readback and verify.
iMPACT also doesn't account for interruption of readback. If readback is interrupted and performed again, configuration data might be corrupted.
iMPACT has implemented the following changes for V2, 2P, and Spartan-3 readback/verify operation to avoid any configuration data corruption.
1. Before each readback operation, a shutdown command is issued and after completion of the readback a start-up command is issued. When the shutdown command is issued, all IOs are 3-stated until the start-up command is issued.
2. If the readback process is interrupted, a special sequence of instructions is delivered to ensure that sequential readbacks will not corrupt the device's configuration memory contents
This enhancement has been included in the latest 6.2i Service Pack available at:
The first service pack containing the enhancement is 6.2i Service Pack 2.